This is a phase I/II multicenter, open-label study of the safety and efficacy of the new sustained release formulation of recombinant human growth hormone (rhGH), Prolease hGH, administered monthly in children with growth failure due to growth hormone deficiency. A maximum of 24 currently treated and 36 naive prepubertal GH-deficient subjects will be enrolled in this study. We have studied 3 children. All have grown at an accelerated rate compared to baseline.